As I do every year, I start thinking of new AMVs for possible entries for next year, and was wondering what the rules were for MMO cutscenes from Final Fantasy XI or XIV. I think quite a few years back, the rules stated that MMOs weren't allowed, but I saw no mention of it in the rules for this year, And FFXI/FFXIV are Japanese base games. So would these be allowed?

I cant say what any future rule may be (and you wont see them for at least 6-9 months) but cutscenes have never been a problem so long as the video games fit the definition of anime and there aren't anything like HUDs in the way.

As long as it fits the definition of anime (you can see it in the FAQ), and it's cutscene footage (not gameplay footage), you should be good, but wait for next year's rules to go up to be absolutely certain.